Low loss semiconductor waveguides for supporting propagation of optical signals over a wide range of wavelengths are achieved by growing at least two epitaxial layers (12,13) of dopant material contiguous along a major surface of each layer to form a heterointerface (14) therebetween. At least one (12) of the epitaxial layers (12,13) includes a sufficient concentration of semiconductor material to cause strain via lattice mismatch substantially at and near the heterointerface (14). The strain induces a change in refractive index such that the heterointerface (14) exhibits a substantially higher refractive index than a portion of each epitaxial layer (12,13) proximate to the heterointerface. The resulting waveguide is capable of supporting propagation of optical signals substantially along the heterointerface (14).

In one example, contiguous epitaxial layers of InP (13) and InGaP (12) form a waveguide for optical signals at wavelengths greater than 0.93 µm. The concentration of Ga in the InGaP epitaxial layer (12) is varied from 10¹⁸ to 10²⁰cm⁻³ to increase the refractive index difference between the heterointerface (14) and the immediate surrounding layers (12,13).